Parameters

One of
EventUtil::SOL_*
constants. Specifies the protocol level at which the option resides. For
example, to retrieve options at the socket level, a
level
parameter of
EventUtil::SOL_SOCKET
would be used. Other levels, such as TCP, can be used by specifying the
protocol number of that level. Protocol numbers can be found by using
the
getprotobyname()
function. See
EventUtil constants
.